[susan53]

A concordancer is a software programme which analyses a corpus of material to see how frquent words and phrases are, what collocations occur etc. To use the lexTutor concordancer to find the results that I mentioned :

a) click on the link.
b) at university (or whatever word/phrase you want to analyse) into the box
c) move to "Choose a corpus". if you want to check Am.Eng click on Brown; If you want written Brit.Eng, click on BNC written; if you want spoken Brit.Eng, click on BNC spoken. Or you can click on All of the above if you don't need to distinguish the variety - try that first. (The other corpora on the list give you the possibility to check specialist uses like Medical or Legal English).
d) Click on Get concordance. You'll see a list of all the uses of "at university" in the corpora you have chosen.

There are other boxes but ignore them for now - they give you more advanced options.